The field windings of synchronous dynamoelectric machines (e.g. motors and generators) can experience reliability issues over time due to wear-out phenomena. In particular the field windings in synchronous generator rotors can experience failure (e.g., poor connection) proximate the field lead(s), one or more braze joint(s), or at another terminal location.
Conventionally, generator field windings are tested manually, by measuring the resistance of the winding via the adjoining slip rings. The resistance is measured eight (8) times, at corresponding angular (rotation) positions of the rotor in order to detect loose connections. In a generator without a field winding fault, these eight measurements should be approximately uniform (e.g., within a given measurement tolerance). As such, the conventional approach includes comparing these eight measurements, and if one or more measurements deviates from the remaining measurements, follow-up is performed on the corresponding location for a likely fault. However, this approach requires on-site measurement of the generator, and time-consuming manual labor.